Chemical ijquxd pbessuke injector



Feb. 9, 1943. a w. DoDGE 2,310,576

CHEMICAL LIQUID PRESSURE INJECTOR Filed April 30, 1940 www Patented Feb. 9, 1943 CHEMHCAL LIQUm PRESSURE INJECTOR Eugene W. Dodge, Shatter, Calif., assignor oi twelve and one-half per cent to Homer Rhyme and twelve and one-half to Chauncey Freemont Wentworth, both oi Long Beach, Calif.

Application April Sil, 194.6, Serial No. 332,455

13 Claims. (Cl. 2.2.1-148) My invention has been especially designed to inject certain liquid chemicals into a gas and oil pipe leading from an oil well. 'Ihese chemicals are used for various specific purposes and are fed only in minute quantities compared with the ilow of the oil and gas with which they become mixed. For this type of use the chemical should be discharged in'to the oil and gas while it still has the heat derived from the formation at the bottom of the well to make a more eiicient application oi' the chemicals, therefore they must be applied against a high gas pressure.

Various attempts have been made to ow the chemical through adjustable valves to allow the supplying in minute quantities such as drop by drop, but these have not been satisfactory due to the obstruction of the valve opening, the chemical change in the material of the valve and obstructions or the like.

A main feature and characteristic of my invention is the supplying of the liquid chemicals by means of the travel of .the liquid developed in great part by the action of capillary attraction through minute channels and for this purpose the control may readily be performed by a feeding wick for the liquid with means to maintain a pressure on the wick to control the capillary ducts or passages. A further feature of my invention is in addition causing the flow of the liquid by gravity through the wick and main taining an equalizing gas pressure on the top oi the liquid in a container substantially equal .to that in the oil pipe or line to which the liquid is supplied in minute quantities. It is to be understood that although my invention has been designed for application to the specic purpose designated that it includes similar injection of liquids such as chemicals into vessels or pipe lines under pressure in which an equalizing pressure is maintained on the surface of the chemical liquid or chemical,

Considered more speciilcally. my invention includes the liquid chemical vessel which is hermetically sealed except for a slightly tapered outlet pipe. or the equivalent located in proximity to the bottom of the container. This may be designated as the Wick tube and within the same I locate a cylindrical wick, then by means of an adjustable plug iitting on the inside of .the wick, I maintain a close contact of the plug with the wick, a desired pressure on the wick and hence control the minute ducts or passages through the wick. In my invention the liquid passing through .the wick and discharged in a slow flow such as drop by drop is lead by suitable connec tions tothe pipes or vessels u'nder pressure and usually having gas therein. In commotion with my invention I employ an equalizing connection which for sake of simplicity is a pipe and tube connection leading through the plug to an up per part of the reservoir vessel, this allowing gas to enter by a communication with the pressure pipes or equivalent under pressure with the gas connection giving a pressure on the passage of the chemical, therefore the ilow ot the chemical through the wick is in part by a capillary attraction through the capillary ducts in the wich and in part by a gravity ow, although the pressure and the hydraulic head of the chemical may be such that the supply of the liquid chemical is practically that due to a capillary flow. My invention also includes a pressure equalizing tube responsive to temperature change -to vary the capillary of .the wick somewhat in accordance with the viscosity ci the chemical.

My invention also includes a welded frame on the reservoir for mounting a liquid gauge glass.

My invention is illustrated in connection with the accompanying drawing, in which:

Fig. 1 is a side elevation .partly broken away on a center line illustrating particularly the capillary control type of valve.

Fig. 2 is a detail section of the connection between the thrust tube and the thrust screw for the plug of the valve.

Fig. 3 is a transverse section on the line 3 3 in the direction of the arrows of the gauge glass assembly.

In accordance with my invention I utilize a sealed reservoir Il which is illustrated as having a cylindrical side l2, a. iat base or bottom i3, a top I4, this latter having a dome or inverted cup I5 with a screw threaded connection by means of the angle ring H5 secured to the top. This allows removal of the dome. A shut-od filler valve 20 is of a type in which a charge of the chemical may be dropped or deposited in ,the reservoir with the escape of but little ii any gas therein and without materially reducing the pressure in the reservoir. A drain plug 22 is located at the bottom of the reservoir and on the side there is a sight glass 25 showing the liquid level.

A capillary valve assembly designated 80 includes a pipe 3| illustrated as having a tapered upper section 32 and a cylindrical lower portion 33 externally threaded at the lower end, al downwardly sloping lower end 36 and a drip discharge duct 35 centrally located. A cylindrical wick il bottom or base 34. A pressure plug 45 is slightly coned on its outer surface to snugly fit the in side of the wick and thrust the wick with an even pressure against the coned or tapered portion 32 of the pipe 3|. This plug has a duct 45 therethrough, a gas inlet pipe 46 connected to the lower end and an equalizing pipe 41 extending upwardly, this having a gas outlet 43. The pipe 41 is connected to an adjusting pressure screw 49 which is threaded through the top of the dome I5 and adjusted by a nut and lock nut. In order to give a slightly loose action and to rotate the screw without rotating the equalizing pipe 41, the screw is indicated as having an annular groove or neck 50, note Fig. 2, and the pipe having a. cotter pin 5| extending through the portion of the pipe and the groove, this being sufficient to transmit the thrust. A coil spring 55 seats on the lower end 34 of the pipe 3| and reacts upwardly against the plug, thus allowing a finer adjustment.

-The drip from the discharge duct 35 ows through a connecting tube 60 which is illustrated as having its upper end 6| with a threaded connection to the lower end of the pipe 3| and having sight apertures with sight tubes 62 with glass windows 63 held in place by apertured caps 54 or any suitable manner. These sight openings are preferably aligned with the orifice end of the discharge duct 35 whereby the operator may note the size and the frequency of the drops discharged. It is manifest that the drops of chemical may be lead in any suitable manner to the structure or device to which the chemical is to be added and for sake of convenience this is indicated as a pipe for the now of gas and oil with a duct 1| connecting through a coupling 12, it being manifest however that the pipe or pressure vessel may be at a considerable distance from the drip valve.

A simple manner of making the sight gauge 25 is by the employment of a metal box 80 open at the front and back and having sides and ends at the back welded to the side |2 of the tank, such sight having apertures 83 at the top and bottom leading into the box. A gasket is tted on the edge of the box, a glass 8| of the heavy pressure boiler type placed on the gasket and both retained in position by a cover strap 82 having a center slot therein. There are removable plugs at the top and bottom of the frame 80 capable of being removed to permit the passage of a swab through the frame back of the glass to clean the glass.

The manner of functioning and operation of my invention is substantially as follows: the same pressure is developed in the reservoir as in the pipe 10 through which the gas or oi1 flows or any other body in a closed chamber under pressure due to the connections 1|, the opening through the discharge .pipe or duct 35, the fluid connection through the duct 45 in the plug by means of the pipe 46 below and the equalizing pipe 41 above, therefore there is no pressure preventing the drip of the liquid. The rate of this drip is controlled by the pressure exerted by the plug 45 on the tubular wick, this manifestly varying the size of the capillary passages through the wick. The greater the pressure, the less the size of these minute passages for the liquid and hence the slower the drip. As above mentioned, this drip has its discharge duct 35 positioned in reference to the sight windows that it may be readily determined not only the size but the rate of the drip of the chemical. The heighth of the liquid in the reservoir may also be determined by the sight glass 25, therefore the liquid may be replenished through the valve 2l whenever this should be necessary. As above mentioned the threading upwardly or downwardly .of the screw 43 and clamping the same in the desired position regulates the thrust onthe plug and hence the compression of the wick.

The equalizing pipe 41 is preferably formed with a readily expanding and contracting section 41' illustrated as a helical coil. This of course could be arranged as a zig-zag coil if desired. With this construction for instance when the reservoir is exposed in conditions of low temperature, the coil somewhat contracts and thus lessens the pressure of the plug 45 against the wick and allows an increase of the capillarity of the wick, hence permitting the more viscous cold liquid to flow through the larger capillary passages. In a contrary manner, under conditions of high temperature. the coils 41' of the equalizing pipe expand and give a Agreater thrust on the plug 41, thus decreasing the passages through the wick.

Should it be desired to use a simpler type of ller valve or merely a ller opening with a plug, it is desirable to employ a shut-of! valve in the pipe connections 1| or the equivalent in order that the gas pressure may be cut oil! from the reservoir. Then when it is desired to replenish the liquid chemical, such shut-off valve completely prevents the flow of the chemical but as the time required to flll the reservoir is quite short this stoppage is immaterial in a continuously operating plant.

Various changes may be made in the details of the construction without departing from the spirit or scope of the invention as defined by the appended claims.

I claim:

1. In a liquid chemical inJector assembly, the combination of a closed vessel forming a reservoir for a liquid chemical, a downwardly tapered pipe connected to the bottom of the vessel, a wick mounted in said pipe and bearing thereagainst for a joint gravity and capillary discharge of the liquid, a plug fitted inside of the wick to exert a thrust on the wick and hence against the tapered pipe to restrict the capillarity of the wick, the plug having a gas duct, an equalizing pipe connected to the upper end of the plug and communicating with the said duct, there being a gas outlet in such pipe to the vessel above the liquid level thereof, means to move the equalizing pipe upwardly and downwardly to vary the pressure of the plug against the wick, a drip discharge duct connected to the lower end of the tapering pipe.

2. A liquid chemical injector including in combination a closed and sealed container having a tapered tubular outlet, a circular wick fitted therein, a plug, means to press the plug against the wick and hence retain the wick with a tight fit between the plug and the tapered outlet, means to discharge the drip from the outlet into a structure having a gas under high pressure and means forming an equalizing connection for such high pressure gas communicating with the upper part of the container.

3. A liquid chemical injector including in combination a closed and sealed container having a tapered tubular outlet at the bottom, a cirandere cular Wick seated therein. a plug engaging the inside of the wick. an equalizing pipe connected to the plug, there being a duct through the plug, the pipe discharging in the upper portion of the container, means to move the pipe longitudinally relative to the wick to vary the pressure of the plug against the wick, the outlet having a discharge means ior the drip of the chemical liquid and a passage for equalizing pressure below the plug and in the upper part of the container.

d. A liquid chemical injector including in combination a closed and sealed container, a tapered tubular outlet from the bottom thereof, a circular wick iitted therein, a tapered plug tted inside of the wick, an equalizing pipe having an expandible and contractible curved section with an outlet at the top, a duct through the plug connecting to the pipe, an adjusting means interconnecting the upper end of the pipe and the top of the container to vary the pressure of the plug on the wick, means forming a drip discharge from the bottom of the tubular outlet and forming a passage for equalizing gas pressure.

5. A liquid chemical injector including in combination a closed and sealed container having a tapered outlet at the bottom, a circular wiel; tted therein, a tapered plug engaging the wiclr and having a duct therethrough, an equalizing pipe connected to the plug and registering with the duct, said pipe having a twist for expansion and contraction, an adjusting means connecting the upper end o the pipe and the top of the container, a spring reacting between the lower part of the tubular outlet and the underside of the plug and a drip discharge from the tapered outlet adapted with the duct and equalizing tube to equalize gas pressure inside the container and. at the drip outlet.

6. A liquid chemical injector including in combination a closed and sealed container, a tapered pipe connected to the bottom of the container, a circular wick mounted in the pipe, a tapered plug engaging the inside of the wick, the plug having a gas duct therethrough, an equalizing pipe having a section expandible and contractible with changes of temperature connected to the plug and communicating with the duct, such pipe having a gas outlet to the container above the level of liquid therein, an adjusting pressure screw having a connection to the equalizing pipe permitting rotation of the screw relative to the non-rotating pipe, the screw being threaded through an upper structure on the container to vary the pressure of the plug on the wick and a drip outlet from the lower portion of the tapered pipe below the plug adapted to conduct the dripping chemical liquid to a hollow structure having gas pressure and to equalize the gas pressure of the hollow structure and the container.

7. In a liquid chemical injector including a closed and sealed container with means for charging a liquid chemical therein, a drip outlet from the container below the level of theliquid therein, there being a gas space above the liquid, a capillary now means operatively connected to the outlet, a pressure device to exert the pressure on the capillary means to regulate the size of the capillary passages, an expandible and contractible device for varying the pressure on the pressure means due to changes of temperature and means to equalize the gas pressure in the space of the container above the liquid and immediately outside of the drip outlet.

8. In a liquid chemical injector including a closed and sealed container with means for charging a liquid therein leaving a gas space above the liquid, a drip outlet connected to the container below the level of the liquid, a capillary wick for flow oi the liquid therethrough to the outlet, a plug bearing on the wick, a tube extending through the plug and having an open end towards the drip outlet and an opening communicating with the gas space of the container, means to adjust the tube to regulate the pressure on the plug.

9. In a liquid chemical injector includi a closed and sealed container with means for charging a liquid therein leaving a gas space above the liquid, a drip outlet connected to the container below the level of the liquid, a capillary wick for now of the liquid therethrough to the outlet, a plug bearing on the wick, a tube extending through the plug and having an open end towards the drip outlet and an opening communicating with the gas space of the container,

-means to adjust the tube to regulate the pressure on the plug, the said tube having an expandible and contractible section responsive to changes or temperature to automatically vary the pressure-oi the plug on the wick as the temperature changes.

10. A liquid chemical injector including -in combination a closed vessel forming a reservoir for a liquid chemical, a tubular connection from the lower part of the vessel, a wick in such tubular connection, the wick forming capillary passages for the chemical liquid and operative for a joint gravity and capillary discharge of 'the liquid, a plug bearing against the wick, the plug having a duct therethrough, an equalizing pipe connected to the plug at the upper end of the duct and having a gas outlet in the vessel above the level of the liquid chemical, an adjusting means connected to the pipe to vary the pressure of the plug on the wick, means forming a gas connection to the duct at the underside of the plug.

ll. In the method of injecting a liquid chemical from a closed liquid chemical reservoir to a hollow structure having gas under pressure by a joint gravity and capillary ow of the liquid chemical comprising causing the gas in the hollow structure to exert a gas pressure on the surface of the liquid in the reservoir to thereby equalize the gas pressure in the reservoir and the hollow structure, manually increasing or decreasing the capillarity of the liquid ow while maintaining the gravity action of the iiow constant whereby on decreasing the capillarity the injection of liquid chemical is decreased and on increasing the capillarity the liquid chemical injection is increased, in. addition causing temperature changes of the chemical liquid in the reservoir to vary the capillarity without innuencing the gravity ow of liquid whereby as the temperature increases the capillarity decreases and as the temperature decreases the capillarity increases thereby compensating for changes of viscosity of the liquid chemical due to its temperature through a. temperature range.

12. In the method of injecting a liquid chemical from a closed liquid chemical reservoir to a hollow structure having a gas under pressure by joint gravity and capillary flow of liquid chemical comprising causing the gas in the hollow structure to exert a gas pressure on the surface of the liquid in the reservoir to thereby equalizethe gas pressure in the reservoir and the hollow structure, causing temperature conduit containing a iluid under pressure, means for maintaining the chemical supply under substantially the same pressure as that of the iiuid, said connecting means including a downwardly extending wick adapted to transmit chemical from the reservoir to the uid by Joint gravit! and capillary action, and means for variably applying pressure to the wick in accordance with temperature conditions.

EUGENE W. DODGE. 

